1. Field of the Invention
The present invention relates to automatic controls for processes, such as treating processes for metal articles, e.g., cans, automotive bodies, coils, etc., in preparation for subsequent painting or lacquering of the articles.
2. Description of the Prior Art
The prior art as exemplified in U.S. Pat. Nos. 3,369,928, 3,515,094, 3,607,453, 4,374,681, and 3,952,698 contains a number of methods and apparatus for automatically monitoring and controlling bath conditions in metal treating operations. Generally, these prior art methods and apparatus employ electrical control circuits which must be particularly designed for each application. Computerized controls or programmable controllers are utilized in some process control applications; however, where large numbers of inputs and outputs must be connected to the controller, the size of the controller to handle such numbers of inputs and outputs generally results in a substantial increase in cost. Furthermore, the prior art control devices are often subject to being misread with respect to warnings and alarms that may be set off due to the nature of the displays and manner of setting forth the warnings or alarms.